[PATCH 3/8] xfs: standardize ondisk to incore conversion for refcount btrees

Darrick J. Wong
2022-12-30T22:38:41Z

Create a xfs_refcount_check_irec function to detect corruption in btree
records. Fix all xfs_refcount_btrec_to_irec callsites to call the new
helper and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_refcount.c | 45 +++++++++++++++++++++++++++++-------------
fs/xfs/libxfs/xfs_refcount.h | 2 ++
fs/xfs/scrub/refcount.c | 14 +++----------
3 files changed, 36 insertions(+), 25 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c
index 6dc968618e66..b77dea10c8bd 100644
--- a/fs/xfs/libxfs/xfs_refcount.c
+++ b/fs/xfs/libxfs/xfs_refcount.c
@@ -120,6 +120,30 @@ xfs_refcount_btrec_to_irec(
irec->rc_refcount = be32_to_cpu(rec->refc.rc_refcount);
}

+/* Simple checks for refcount records. */
+xfs_failaddr_t
+xfs_refcount_check_irec(
+ struct xfs_btree_cur *cur,
+ const struct xfs_refcount_irec *irec)
+{
+ struct xfs_perag *pag = cur->bc_ag.pag;
+
+ if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN)
+ return __this_address;
+
+ if (!xfs_refcount_check_domain(irec))
+ return __this_address;
+
+ /* check for valid extent range, including overflow */
+ if (!xfs_verify_agbext(pag, irec->rc_startblock, irec->rc_blockcount))
+ return __this_address;
+
+ if (irec->rc_refcount == 0 || irec->rc_refcount > MAXREFCOUNT)
+ return __this_address;
+
+ return NULL;
+}
+
/*
* Get the data from the pointed-to record.
*/
@@ -132,6 +156,7 @@ xfs_refcount_get_rec(
struct xfs_mount *mp = cur->bc_mp;
struct xfs_perag *pag = cur->bc_ag.pag;
union xfs_btree_rec *rec;
+ xfs_failaddr_t fa;
int error;

error = xfs_btree_get_rec(cur, &rec, stat);
@@ -139,17 +164,8 @@ xfs_refcount_get_rec(
return error;

xfs_refcount_btrec_to_irec(rec, irec);
- if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN)
- goto out_bad_rec;
-
- if (!xfs_refcount_check_domain(irec))
- goto out_bad_rec;
-
- /* check for valid extent range, including overflow */
- if (!xfs_verify_agbext(pag, irec->rc_startblock, irec->rc_blockcount))
- goto out_bad_rec;
-
- if (irec->rc_refcount == 0 || irec->rc_refcount > MAXREFCOUNT)
+ fa = xfs_refcount_check_irec(cur, irec);
+ if (fa)
goto out_bad_rec;

trace_xfs_refcount_get(cur->bc_mp, pag->pag_agno, irec);
@@ -157,8 +173,8 @@ xfs_refcount_get_rec(

out_bad_rec:
xfs_warn(mp,
- "Refcount BTree record corruption in AG %d detected!",
- pag->pag_agno);
+ "Refcount BTree record corruption in AG %d detected at %pS!",
+ pag->pag_agno, fa);
xfs_warn(mp,
"Start block 0x%x, block count 0x%x, references 0x%x",
irec->rc_startblock, irec->rc_blockcount, irec->rc_refcount);
@@ -1871,7 +1887,8 @@ xfs_refcount_recover_extent(
INIT_LIST_HEAD(&rr->rr_list);
xfs_refcount_btrec_to_irec(rec, &rr->rr_rrec);

- if (XFS_IS_CORRUPT(cur->bc_mp,
+ if (xfs_refcount_check_irec(cur, &rr->rr_rrec) != NULL ||
+ XFS_IS_CORRUPT(cur->bc_mp,
rr->rr_rrec.rc_domain != XFS_REFC_DOMAIN_COW)) {
kfree(rr);
return -EFSCORRUPTED;
diff --git a/fs/xfs/libxfs/xfs_refcount.h b/fs/xfs/libxfs/xfs_refcount.h
index c89f0fcd1ee3..fc0b58d4c379 100644
--- a/fs/xfs/libxfs/xfs_refcount.h
+++ b/fs/xfs/libxfs/xfs_refcount.h
@@ -117,6 +117,8 @@ extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
union xfs_btree_rec;
extern void xfs_refcount_btrec_to_irec(const union xfs_btree_rec *rec,
struct xfs_refcount_irec *irec);
+xfs_failaddr_t xfs_refcount_check_irec(struct xfs_btree_cur *cur,
+ const struct xfs_refcount_irec *irec);
extern int xfs_refcount_insert(struct xfs_btree_cur *cur,
struct xfs_refcount_irec *irec, int *stat);

diff --git a/fs/xfs/scrub/refcount.c b/fs/xfs/scrub/refcount.c
index 9423aad28511..c2ae5a328a6d 100644
--- a/fs/xfs/scrub/refcount.c
+++ b/fs/xfs/scrub/refcount.c
@@ -340,24 +340,16 @@ xchk_refcountbt_rec(
{
struct xfs_refcount_irec irec;
xfs_agblock_t *cow_blocks = bs->private;
- struct xfs_perag *pag = bs->cur->bc_ag.pag;

xfs_refcount_btrec_to_irec(rec, &irec);
-
- /* Check the domain and refcount are not incompatible. */
- if (!xfs_refcount_check_domain(&irec))
+ if (xfs_refcount_check_irec(bs->cur, &irec) != NULL) {
xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+ return 0;
+ }

if (irec.rc_domain == XFS_REFC_DOMAIN_COW)
(*cow_blocks) += irec.rc_blockcount;

- /* Check the extent. */
- if (!xfs_verify_agbext(pag, irec.rc_startblock, irec.rc_blockcount))
- xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
-
- if (irec.rc_refcount == 0)
- xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
-
xchk_refcountbt_xref(bs->sc, &irec);

return 0;